being unclaimed, he was signed by the Oakland Raiders in 1979 and became a key player on special teams, which included the role of long snapper. Being the son of a college professor, he was scholarly and enjoyed the mastery of words, he also quoted famous authors and volunteered on different occasions poems, some of which were written by him. His eccentricities helped him fit in with the Raiders, even if he wasn't tailored to the renegade mold. He finally agreed to play the tight end position and after three seasons of unspectacular statistics (including the Raiders' Super Bowl winning campaign in 1980, in which his only reception of the entire year was a 1-yard touchdown catch in the opening round of the playoffs), Christensen broke out in 1982, catching 42 passes for 510 yards and four touchdowns during the strike-shortened season, helping the Raiders tie the Washington Redskins for the best record in the NFL. The next year, Christensen caught 92 passes for a career-high 1,247 yards and 12 touchdowns and earned the first of his five trips to the Pro Bowl for his efforts. His total catches led the NFL, making him the second tight end to ever do this (Kellen Winslow was the other). The Raiders finished the season with a resounding 38–9 victory over the Washington Redskins in Super Bowl XVIII. Christensen topped 1,000 yards again in 1984, catching 82 passes in the process. He hit 80 receptions again the following year, missing 1,000 yards by just 13 yards. The 1986 NFL season was Christensen's last big one statistically. He ended the year with a career-high, league-leading 95 receptions for 1,153 yards and eight touchdowns. The 95 receptions would stand as the most by an NFL tight end in a single season until Ben Coates totaled 96 in 1994. Christensen also became the first tight end in history to catch 90 passes in each of two seasons. Christensen's 1987 campaign was cut short due to the players' strike, but in 12 games he still managed to catch 47 balls (a little fewer than four per game). His 663 yards averaged to 14.1 yards per reception, a career-high in seasons where he caught at least 40 passes. In Christensen's final year, he missed more than half the season with injuries. He only caught 15 passes, with none going for touchdowns, and then he retired from pro football.